Check out my new article for Foreign Policy: “The Rise of al-Qaeda in Syria”

President Barack Obama’s administration is reportedly planning to designate the Syrian jihadist group Jabhat al-Nusra (“the Support Front”) as a terrorist organization. The group, which was firstannounced in late January 2012, has become a growing part of the armed opposition due to its fighting prowess — perhaps no surprise, as many of its fighters honed their skills in battlefields in Afghanistan, Iraq, Libya, and Yemen. As a result, Jabhat al-Nusra has carved out an important niche in the fight to oust the Syrian regime even as it remains outside of the mainstream opposition.

The U.S. administration, in designating Jabhat al-Nusra, is likely to argue that the group is an outgrowth of the Islamic State of Iraq (ISI). While there is not much open-source evidence of this, classified material may offer proof — and there is certainly circumstantial evidence that Jabhat al-Nusra operates as a branch of the ISI.

There’s no denying that Jabhat al-Nusra is deadly: It has claimed responsibility for more than 500 attacks since its creation, including a series of suicide bombings. Unique among rebel groups operating in Syria, it has also earned the legitimacy of top global jihadist ideologues, who have called for grassroots supporters across the world to help fund or join up with the group. And foreign fighters have answered the call: Based on data from al Qaeda’s online forums, of the 46 individuals for which the forums have provided “martyrdom” notices and announced their group affiliation, 20 fought with Jabhat al-Nusra. Since Oct. 1, almost all of the notices that mention affiliation have reported that the fighter was aligned with Jabhat al-Nusra.